is it possible to make CUPS daemons cooperate between themselves?

Mulyadi Santosa [mulyadi.santosa at gmail.com]

Wed, 9 Jul 2008 17:26:55 +0700

Hi gang...

Sorry if the subject sounds confusing, but I wonder, is it possible?
AFAIK, each CUPS daemons manage its own queue on the node's own
disk...and by design I don't see CUPS is designed as cooperative
daemon.

By "cooperative" I mean something like having unified print spool,
unified and shared printer device's name among CUPS daemons...and so
on.

> Hi gang...
>=20
> Sorry if the subject sounds confusing, but I wonder, is it possible?
> AFAIK, each CUPS daemons manage its own queue on the node's own
> disk...and by design I don't see CUPS is designed as cooperative
> daemon.

But CUPS is designed to be highly cooperative. Every CUPS daemon can
send out broadcasts to the local subnet or multicast packets that
announce all available printer queues to all other CUPS servers. You can
also do failover, balancing and introduce TCP polling in order to cross
routers or WANs. You just have to define the access lists accordingly.

> But CUPS is designed to be highly cooperative. Every CUPS daemon can
> send out broadcasts to the local subnet or multicast packets that
> announce all available printer queues to all other CUPS servers. You can
> also do failover, balancing and introduce TCP polling in order to cross
> routers or WANs. You just have to define the access lists accordingly.

Interesting, I failed to see those option in CUPS online
documentation. Can you kindly point me to some URLs that explain how
to do it?

> Hi...
>
> On Wed, Jul 9, 2008 at 5:52 PM, René Pfeiffer <lynx@luchs.at> wrote:
> > But CUPS is designed to be highly cooperative. Every CUPS daemon can
> > send out broadcasts to the local subnet or multicast packets that
> > announce all available printer queues to all other CUPS servers. You can
> > also do failover, balancing and introduce TCP polling in order to cross
> > routers or WANs. You just have to define the access lists accordingly.
>
> Interesting, I failed to see those option in CUPS online
> documentation. Can you kindly point me to some URLs that explain how
> to do it?

I forgot to include this in my first reply, but it seems the CUPS people
have restructured the documentation. I can give you some lines from my
local CUPS server here in the office.

By having this you should see network broadcasts from your CUPS server
every 60 seconds. This is sufficient for all other CUPS servers in the
network to synchronise the printer queues. You can now send a print job
to any CUPS server and they sort out where the job has to go. It works
perfect in our office and with the satellite CUPS servers on systems
connecting via VPN.

> [...]
> Big thanks! Actually I was looking on those "Browse" options but never
> realize those are the ones. I'll try to test your configuration
> snippet real soon.

I see. The config works in our LAN. You have to be careful about
encryption; the recent CUPS installations on Debian default to HTTPS
instead of HTTP (at least CUPS tried to switch to HTTPS when I upgraded
our CUPS server). This can be turned off.

I've done my homework and tried a net.search, and still have no idea
what a "poor man" hamburger in Indonesia is. Please do share? (Drat that
net.protocols still have trouble with sending food over the aether!)